FILM-IDENTIFICATION 3843714 - Caterpillar

Static Check Of The Timing Gear Position
Illustration 1 g02416818
Front gear group
(1) Timing marks
(2) Camshaft gear
(3) Crankshaft gear
(4) Oil pump idler gear assembly
(5) Oil pump drive gear
(6) Timing marks
(7) Idler gear
(8) Timing marksThe basis for the correct fuel injection timing and the valve mechanism operation is determined by the alignment of the timing for the front gear group. Pin the engine at top center of piston 1 to check the timing marks. Refer to Testing and Adjusting, Finding Top Center Position for No. 1 Piston for the correct procedure.For 3408E and 3412E HEUI drive gear and camshaft gears are marked by the letter "H". These two marks must align.The 3412C does not require timing to be aligned with the fuel pump gear. The "H" on the camshaft gear should be at 12 o'clock.The timing marks on gears (2), (3), and (7) need to be aligned to provide the correct relationship between piston movement and valve movement.